ABSTRACT
58Using the complex non‐autonomous Ginzburg‐Landau model, oscillatory mode of thermal instability is investigated for oscillatory convective flow. The non‐Newtonian fluid is considered for the existence of oscillatory mode of convection. The perturbation technique is used to simplify nonlinear problem. The Nusselt number is obtained numerically in terms of the system parameters, to study heat transfer in the medium. The effect of viscoelastic fluid parameters, stress relaxation λ 1 $ \lambda_{1} $ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315187860/1e135b13-0e67-4cd8-a124-16c08526ea1f/content/inline1.tif"/> and strain retardation λ 2 $ \lambda_{2} $ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315187860/1e135b13-0e67-4cd8-a124-16c08526ea1f/content/inline2.tif"/> times on heat transfer have been discussed. Thermal modulation is considered to control the heat transfer in the medium. This modulation destabilizes at low frequencies and stabilizes at high frequencies, but this trend is reverse for amplitude of modulation. Finally, it is found that heat transfer enhances for oscillatory mode than in stationary case.
